HCG Blood Test: How It Works and What to Expect

Wondering if you might be pregnant and looking for answers you can trust? The HCG pregnancy test is a reliable tool that works as an indicator of pregnancy early by measuring hormone levels, which can help you take the next step with confidence.

What is hCG pregnancy test?

An hCG pregnancy test checks for the presence of the hormone human chorionic gonadotropin (hCG) in your blood or urine to confirm if you’re pregnant. hCG levels rise rapidly in early pregnancy, making this test one of the most accurate ways to detect pregnancy in the first few weeks—even before a missed period. It’s commonly used in both home pregnancy test kits and clinical settings to confirm early pregnancy.

What are hCG levels in pregnancy?

Human chorionic gonadotropin (hCG) is a hormone that plays a key role in early pregnancy. It is produced by the placenta shortly after a fertilised egg attaches to the lining of the uterus. This hormone is what pregnancy tests detect in urine or blood to confirm if you’re pregnant.

In a healthy early pregnancy, hCG levels rise rapidly—usually doubling every 48 to 72 hours. These rising levels help maintain the pregnancy by stimulating the ovaries to produce another important hormone: progesterone. Progesterone supports the uterine lining and creates a stable environment for the developing embryo.

Tracking hCG levels through blood tests can also help doctors assess how the pregnancy is progressing, especially in the first few weeks. Abnormal hCG levels may indicate abnormal pregnancy issues such as ectopic pregnancy, miscarriage, or, in rare cases, multiple pregnancies (like twins or triplets).

Types of hCG pregnancy tests

There are two main types of hCG tests used to detect and monitor pregnancy: qualitative and quantitative.

Qualitative hCG test

This test simply checks whether hCG is present in the body.

• Provides a yes or no answer to confirm pregnancy.

• Commonly used in home pregnancy test kits and basic lab tests.

• Does not measure the exact amount of hCG.

• A positive result typically means pregnancy.

• A negative result may indicate no pregnancy or that it is too early for hCG to be detected.

Quantitative hCG test (Beta-hCG test)

This test measures the precise level of hCG in the blood.

• Offers an exact numerical value of hCG concentration.

• Commonly used in clinical settings to track early pregnancy progression.

• Helps healthcare professionals detect conditions such as ectopic pregnancy, miscarriage, or molar pregnancy.

• Useful for monitoring hCG trends in fertility treatments or after pregnancy loss.

Both tests play a crucial role in early pregnancy detection and monitoring. Your healthcare provider will recommend the appropriate test based on your symptoms and medical history.

Why would you need an hCG pregnancy test?

An hCG test is commonly used to confirm and monitor pregnancy. It helps in several important situations, including:

• Early pregnancy confirmation: 

  • To detect pregnancy even before symptoms appear or a period is missed.

• Monitoring pregnancy progression: 

  • To check if hCG levels are rising normally, which indicates a healthy pregnancy.

• Diagnosing ectopic pregnancy:

  • To identify pregnancies that occur outside the uterus, which can be dangerous.

• Assessing risk of miscarriage:

  • Falling or irregular hCG levels may suggest a potential pregnancy loss.

• Post-miscarriage or abortion follow-up: 

  • To ensure that hCG levels return to normal, confirming that no pregnancy tissue remains.

If you're unsure about your symptoms or would like clarity on your pregnancy status, request an appointment with us and we can guide you on your next steps.

When should you consider an hCG pregnancy test?

An hCG pregnancy test may be recommended or considered in many situations, especially during the early stages of pregnancy. Here are some common reasons to take the test:

• Missed menstrual period:

  • A missed period is one of the earliest and most common signs of pregnancy. Testing for hCG can help confirm whether pregnancy is the cause.

• Experiencing early pregnancy symptoms: 

  • Symptoms such as nausea, vomiting, fatigue, breast tenderness, mood changes, or frequent urination may indicate rising hCG levels in the body.

• After unprotected sexual intercourse:

  • If there is a possibility of pregnancy and no contraception was used, an hCG test can help provide early confirmation.

• During fertility treatments: 

  • Individuals undergoing assisted reproductive procedures like IUI or IVF often take hCG tests to check for successful implantation.

• Unusual bleeding or pelvic pain: 

  • An hCG test may be used to investigate the cause of symptoms and help identify issues such as ectopic pregnancy or early miscarriage.

If there is any uncertainty about early pregnancy signs or symptoms, you can request an appointment with Thomson Medical to determine the appropriate timing for testing and ensure accurate interpretation of results.

How to prepare for an hCG pregnancy test?

Preparation for an hCG test depends on whether it is a urine-based or blood-based test. Here’s what you need to know:

Urine hCG test

• Use first-morning urine: 

  • This first morning urine sample is typically more concentrated, making it easier to detect low levels of hCG in early pregnancy.

• Avoid excessive fluid intake beforehand: 

  • Drinking too much water before the test can dilute the urine and affect the accuracy of the result.

Blood hCG test

• No fasting or special preparation is required.

• Inform your doctor about any medications or supplements you are taking, as some may influence the results.

The best time to use an hCG pregnancy test

Timing plays a crucial role in ensuring accurate hCG test results. Here's when to take each type:

• Urine hCG test: 

  • For the most reliable result, take the test about one week after a missed period. Using first-morning urine is recommended, as it contains the highest concentration of hCG.

• Blood hCG test: 

  • A blood test can detect pregnancy as early as 6 to 8 days after ovulation, even before a missed period. It’s often used in clinical settings to confirm early pregnancy or monitor progression.

Reading hCG pregnancy test results

Interpreting hCG levels can give valuable information about the status of a pregnancy, especially during the early weeks. Here’s what different trends in hCG levels may indicate:

• Increasing hCG levels:

  • A steady rise in hCG—typically doubling every 48 to 72 hours—is a positive sign of a healthy and progressing pregnancy.

• Slow-rising hCG levels: 

  • If hCG levels rise more slowly than expected, it may suggest a potential complication, such as an ectopic pregnancy (where the embryo implants outside the uterus), trophoblastic disease or an increased risk of miscarriage. 

  • Further evaluation with ultrasound or follow-up tests may be required.

• Declining hCG levels:

  • A drop in hCG levels might indicate a failing pregnancy, such as an impending or completed miscarriage. However, doctors will typically confirm this with additional tests before making a diagnosis.

Factors that could affect test results

False positives (Test shows positive, but not pregnant)

• Use of fertility medications that contain hCG.

• Recent miscarriage or abortion – hCG can remain in the bloodstream for several weeks.

• Certain medical conditions, such as certain types of cancer, ovarian cysts or some types of tumours.

False negatives (test shows negative, but actually pregnant)

• Testing too early: hCG levels may not be high enough to detect.

• Diluted urine: Drinking too much fluid before a urine test can lower hCG concentration.

• Expired or faulty test kit: May affect the accuracy of results.

If your result is unclear or doesn’t match your symptoms, it’s best to repeat the test after a few days or request an appointment with us for further evaluation.

Price of an hCG pregnancy test in Singapore

The cost of an hCG pregnancy test in Singapore can vary based on several factors. These include the type of test (urine or blood), whether it is performed at a public or private healthcare facility, and whether the test is part of a larger fertility or diagnostic package.

At subsidised rates in public hospitals or polyclinics, a basic urine hCG test typically costs between SGD 10 and SGD 30. A blood hCG test (quantitative) may range from SGD 30 to SGD 80, depending on the lab and whether additional consultations or follow-ups are required. Prices may be higher for non-subsidised patients or referrals from private clinics.

In private clinics or hospitals, the cost of an hCG blood test can range from SGD 50 to over SGD 150. If the test is conducted as part of a fertility consultation or package, prices may vary further, especially if multiple tests or follow-up appointments are included.

• Some key factors that may affect the total cost include:

• Whether the test is urine-based or blood-based

• Location and type of facility (public or private)

• Need for specialist consultation

• Whether the test is part of a fertility or diagnostic package

The information provided above is intended for general reference only. For detailed fee information and payment options, please consult your healthcare provider directly. Request an appointment with our specialists at Thomson Medical today for a detailed price breakdown and a personalised care plan.

FAQ

What does an hCG test check for?

How early can an hCG test detect pregnancy?

What hCG level confirms pregnancy?

Pregnancy is typically confirmed when hCG levels reach 5–25 mIU/mL or higher in blood samples. In early pregnancy, hCG levels should double every 48 to 72 hours, indicating healthy progression. Levels below 5 mIU/mL are usually considered negative for pregnancy. These levels are measured in milli-international units of hCG per millilitre of blood (mIU/mL).

What if I feel pregnant but the hCG test is negative?

Can you have hCG in your body and not be pregnant?

When is hCG highest in the day?

hCG levels in the body remain relatively stable throughout the day. However, for urine-based pregnancy tests, hCG is most concentrated in the first-morning urine, especially in early pregnancy. Testing at this time improves the chances of detecting even low levels of the hormone for more accurate results.

Will hCG show up in week 1?

A week after fertilisation, hCG levels are usually still too low to detect. However, if counting from the first day of your last menstrual period (LMP), which is how pregnancy is typically measured, hCG may begin to appear in blood tests around 6–8 days after ovulation—roughly 3–4 weeks gestational age. For most accurate results, wait until at least one day after a missed period to take a urine pregnancy test.

How quickly does hCG rise after implantation?

hCG levels begin to rise within 24 to 48 hours after implantation. Once implantation occurs—typically 6 to 10 days after ovulation—hCG is released by the developing placenta and starts doubling approximately every 48 to 72 hours in early pregnancy. This rapid increase allows early detection through blood tests as soon as 6–8 days after ovulation and through urine tests a few days later.

Can I check hCG levels at home?

The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations and tailored advice, please consult a specialist at Thomson Medical. Request an appointment with Thomson Medical today.